Stress Can Hinder Prostate Cancer Treatments

Stress, which typically accompanies a cancer diagnosis, may promote the growth and spread of prostate by reducing the effectiveness of therapy, new research shows.

The study, conducted by researchers at Wake Forest Baptist Medical Center, suggests stress-reducing drugs and other techniques may be critical for patients who are undergoing cancer treatments to help boost their immune systems and strengthen the power of treatments.

"We are at the very beginning of understanding complex stress-cancer interactions with multifaceted responses to stress that affect cancer cells," said George Kulik, who helped conduct the study, published in the Journal of Clinical Investigation. He added that he hopes the study findings may help “to predict whether and how a given tumor will respond to stress and anti-stress therapies."

For the study, Wake Forest researchers tested the effects of behavioral stress on laboratory mice implanted with human prostate cancer cells and treated with an experimental cancer drug. When the mice were kept calm and free of stress, the drug destroyed prostate cancer cells and blocked tumor growth, the researchers found. But when the mice were stressed, the cancer cells didn't die and the drug did not halt the tumor growth.

A second study, involving mice genetically modified to develop prostate cancer, found that the tumors grew when the animals were exposed to repeated stress, even when they were treated with bicalutamide, a drug used to treat prostate cancer.

The Wake Forest Baptist researchers determined that stress affects production of epinephrine, a hormone also known as adrenaline, that sets off a cellular chain reaction that may promote cancer progression, Kulik said. But when the mice were given beta-blocker drugs, which counteracts the effects of epinephrine, stress did not promote prostate tumor growth.

"Providing beta-blockers to prostate cancer patients who had increased epinephrine levels could improve the effectiveness of anti-cancer therapies," Kulik said. "Our findings could be used to identify prostate cancer patients who will benefit from stress reduction or from [drugs that block] stress-inducing signaling."

The study was funded, in part, by the U.S. Department of Defense and the National Cancer Institute.